Friday, May 27, 2005 PrimEx meeting Minutes
Attending:
E. Clinton, R. Demirchyan, L. Gan, A. Gasparian, M. Ito, D. McNulty, V. Mochalov, M. Payen, A. Teymurazyan,
On phone -
A. Bernstein
agenda:
1. Appointment of secretary: all
2. Review of last meeting's minutes: all
3. Normalization status: Aram
4. Tagger work: Eric
5. Review of project list: all
1. Raphael was nominated for secretary.
Liping has been volunteered for the next week's secretary
(and then next to that - Ashot).
2. Minutes of last meeting approved.
3. Aram concludes: the miss-reconstruction of double photons in TAC runs, in 5% of events, are caused by timing
shift. Eric's recalibration of T-counters drops 5% down to 0.7%. Normalization studies are close to
finalized. Aram needs another week for TAC studies. Next step is creating the luminosity tables for production
runs. Recommendation arisen to make one page, at least, summary on the lumi calculation algorithm including
timing and live time corrections. Next week Aram will present the way and the format of lumi tables.
4. Eric presented studies on double hits in tagger T-counters. In particular, T-counter 9 (T-channel 17) turns out
fires every time when any T-counter fires in trigger i.e. in cases when the trigger is formed by other
counter(s) with TAGT multiplicity more than one. Kind of, physical timing for #9 is by 10ns/20TDC counts shorter
than mean trigger timing. Eric has implemented this addition (software, in his "area"). So, true photons can be
recovered in TAGTHIT by means of incurring an extra peak like T-counter 9. The spurious peak is still within
the TT and ET timing windows.
Plots can be found in Eric's page: http://www.jlab.org/~eclinton/27May2005/index.html
5. Review of project list: http://www.jlab.org/primex/weekly_meetings/slides_2005_05_20/tasks.txt
Mainly the first items, the topics of calibration, normalization and Monte Carlo were discussed.
More question than answers. Aaron suggested to prioritize the list. Other suggestions - to make more
"discussable" the list. Mark's decision was to postpone the discussion to the next meeting after he will
"work" on list with Ashot and then represent it.